Many new types of medium sized hetero-cyclic compounds were synthesized by [2,3] sigmatropic rearrangement of alpha-aryl cyclic ammonium methylides or sulfonium methylides which were generated by fluoride ion-induced desilylation of alpha-aryl-[(trimethylsilyl)methyl]-cyclic ammonium or sulfonium salts in DMF or DMSO at room temperature.The results have been published in J.Org.Chem. (2 articles) and J.Chem.Soc., Perkin Trans 1.(4 articles).